Re: Passing a GUI handle to a socket and Postmessage back to GUI
It is important that this message handler function provide the exact
function signature that is expected by the message map dispatcher.
Assuming you are using ON_MESSAGE in the message map, this function must
be declared:
LRESULT SocketWindow::OnSockMSG(WPARAM wParam, LPARAM lParam)
This will avoid possible stack corruption and 64-bit compatibility issues.
Okay, I have changed "UINT" and "long" to WPARAM and LPARAM
respectively. Everything still works as before.
In a sockets context it is extremely confusing to name CServer 'client'.
In fact, your MySocket class is the server.
Good point. It is confusing. I will change that variable name.
This is workable, but a better OOP design would pass 'this' to the
constructor of the client. Then the client would depend only on the code
that creates it.
Your answer here is what I thought - there must be a better way to
do this, however, I still am not sure how to accomplish it.
How would I pass "this" to the client and from where? I assume I
would need to get the HWND from the "this" pointer. Correct?
Thanks,
KW
"Scott McPhillips [MVP]" <org-dot-mvps-at-scottmcp> wrote in message
news:%23uYK0mmoJHA.6060@TK2MSFTNGP05.phx.gbl...
"KW" <KW@there.com> wrote in message
news:OZcqxPmoJHA.1252@TK2MSFTNGP03.phx.gbl...
I have a MDI application with several child windows and a TCPIP server. I
want to pass the handle (of one child) to a server socket class so it can
post a message to the child window when data is received. When the data is
received by the child window, a listbox will display the data.
I have it working, but I wonder if there is a better way of passing (or
getting) the handle. I have to pass it twice to get it into the
OnReceive() Handler of CServer.cpp.
// Click a button and start the listener - couldn't get it to work in
constructor (handle not created yet?) - "SocketWindow" is UI class
void SocketWindow::OnButton1()
{
sockServ = new MySocket(CWnd::m_hWnd); //Is this the best way to
get/pass the handle?
sockServ->Create(1001);
sockServ->Listen();
}
The window's handle does not exist during the window's constructor. The
window's OnCreate or OnInitialUpdate will be called when the handle first
becomes available.
void SocketWindow::OnSockMSG(UINT wParam, long lParam)
{
CString * ptr = (CString *)wParam;
m_ListBoxAdder.AddString(*ptr);
delete(ptr);
}
It is important that this message handler function provide the exact
function signature that is expected by the message map dispatcher.
Assuming you are using ON_MESSAGE in the message map, this function must
be declared:
LRESULT SocketWindow::OnSockMSG(WPARAM wParam, LPARAM lParam)
This will avoid possible stack corruption and 64-bit compatibility issues.
// These 4 lines are from MySocket.h
public:
MySocket(HWND);
virtual ~MySocket();
CServer client;
HWND ChildWindowHandle;
In a sockets context it is extremely confusing to name CServer 'client'.
In fact, your MySocket class is the server.
// Constructor MySocket.cpp
MySocket::MySocket(HWND MyHandle)
{
ChildWindowHandle = MyHandle;
}
// MySocket.cpp
void MySocket::OnAccept(int nErrorCode)
{
if (nErrorCode == 0)
{
this->Accept(client);
// IS THIS A PROBLEM? "client" is declared in CServer.h
client.HandleToChld = ChildWindowHandle ;
}
}
This is workable, but a better OOP design would pass 'this' to the
constructor of the client. Then the client would depend only on the code
that creates it.
--
Scott McPhillips [VC++ MVP]